Aeroplane



Mar. 3, 1 925. 1,528,335

D. K. JETTE AEROPL-ANE Filed Nov. 6, 1922 2 Sheets-Sheet 1 Mar. 3, 1925.

D. K. JETTE AEROPLANE Filed Nov. 6, 1922 2 Sheets-Sheet 2 Patented Mar. 3, 1925. I

UNITED Y STATES 1,528,335 PATENT OFFICE.

navm K. JE'm'n; or msxoe, swnnnn.

nnaormnn Application filed November 6, 1922. Serial No. 599,295.

To aZZivhom. it may concern;

Be it known that I, DAVID K. Jn'rrn, a citizen ofthe Kingdom of Sweden, residing at Midskog, Sweden, have invented new and useful Improvements in Aeroplanes, of which the following is'a specification.

This invention relates to aeroplanes, and especially to aeroplanes having both one or more tractor propellers and one or more lift ing propellers.

The object of the invention is in general to improve the effectivity of such aeroplanes. More particularly the invention has for its object to provide means whereby the air currents produced by the peration of the said two types of propellers are prevented from having any undesired action on the supporting planes and the air currents produced by the tractor propeller or propellers are prevented from disturbingthe operation of the lifting propeller or propellers.

One feature. of the invention comprises the provision at the front end of the aeroplane housing of a freely rotatable tapering nose having spiralribs on its external surface so placed as'to cause the nose upon the forward movement ofthe aeroplane to rotate in opposite direction to the rotation of the tractor propeller.

This and other features of the invention will appear from the detailed description following hereinafter with reference to the accompanying drawing In which, Figure 1 is a side-elevation of an aeroplane accordin to this invention.

Fig. 2 is a plan view thereof. Fig. 3 is an end view of the aeroplane. Figs. 4-6, inclu sive, show details of the propellers. All figures of the drawings are of a substantially diagrammatic nature.

In the drawing I have illustrated an aeroplane, having but one tractor propeller and one lifting propeller, it should be noted, however, that the invention may equally well be adapted to aeroplanes having more than one propeller of each of said two types.

The fuselage 1 of the aeroplane is spoolsha ed and is provided with a bulbous roof 2. he fuselage may, for instance, be manufactured from wood, steel or other metal, or from raw silk fabric strengthened by a suitable metal. The bottom of the fusela e is of a design rendering the bottom su cient-ly strong and flexible and at the same time making it water-ti ht. Securedto the under side of the fuselage is two sets of pontoons 3 of any appropriate design. Attached to the sides of the fuselage are the main supporting planes 4 and 5. while at the rear end of the fuselage, rear horizontal planes 6 are rigidly attached'to the fuselage. Besides the said horizontal rear planes 6 rear vertical planes or wings 7 are provided at both sides of the fuselage as well as at the upper side thereof. Mounted in aliuement with the uppermost vertical wing 7 is a vertical rudder '8 and mounted in alinement with the rear .horizontal planes'6 are two horizontal rudders 9. At the front end of the fuselage, a tractor propeller 10 is mounted. Mounted above the fuselage with its centre just above the highest point of the bulbous roof 2 is a lifting propeller 11.

Mounted immediately behind the tractor propeller 10 is a nose 12 capable of rotating freely on the shaft of the tractor propeller. Said nose has a rounded shape somewhat like that of a projectile and carries on its external surface spiral ribs 13 so positioned as .to cause the nose due to the air resistance to rotate 'in a direction opposite to the direction of rotation of the tractor propeller when the aeroplane is moving.

The tractor propeller 10 comprises a set of cast blades 14 inserted between a hub 15 and an outer annular rim 16, as is more clearly shown in Fig. .4. Each blade comprises two curved sheet metal plates connected together at their edges and forming between themselves a closed air-space, as is indicated in Fig. 6, wherein a blade 14 is shown. The annular rim 16 serves to collect and guide the air current thereby prevepting the same from being spread to the s1 es.

The lifting propeller 11 likewise comprises a series of cast blades 17 as shown in Fig. 5. Each such blade is of a construction similar to the construction of the blades of the tractor propeller, that is, comprises two curved sheet metal plates connected at their edges and inserted between a hub and an outer, annular rim. Said rim may, preferably,be conical in cro'ss-section to reduce the air resistance on the propeller. At tached to the shaft of the lifting propeller is a series of turbine blades 18, said blades serving to rotate thepropeller due to the air resistance when no power is transmitted to the lifting propeller. The lifting propeller is situated approximately between the main supporting planes, as seen in planview (Fig. 2).

The' upper pair of the main supporting planes 4 are each attached to the roof 2 in such a way as to form a space 19 between the inner edge of each plane and the roof in order to enable the air forced downwardly by the lifting propeller to pass down below the planes 4.

Provided along a portion of the periphery of the lifting propeller at the side thereof, where the propeller blades move forwardly, is ashield 20 covering the periphcry of the ropeller at said portion. The front end 0 the shield 20 is bent in the forward direction of the aeroplane, as shown. Provided immediately below the lifting propeller is a network, Fig. 5, which is for the purpose of preventing a rope of a parachute that may be secured tothe roof 2 of the fuselage, from being caught by the lifting propeller blades.

In the forward movement of the aeroplane the nose ordrum 12 will be caused to rotate due to the air current from the tractor propeller acting on the helical ribs, the nose, as stated .before, being thus caused to rotate in opposite direction to the direction of rotation of the tractor propeller. The nose, when rotating, provides a suitable guiding of the air current from, the tractor propeller thereby preventing said air from combining with the air current from the lifting propeller into a current having a disturbing efiect on the aeroplane.

The shield 20 deflects the air from the side of the lifting propeller where the blades thereof are movingforwardly. This will remove any tendency ofthe lifting propeller to tilt the aero lane. The air current produced by the li ing propeller will be passed downwardly along the inclined roof 2 and through the spaces 19 and will then sweep along the under side of. the main planes 4.

The propellers 10 and 11 and the rotary steeper angle than machines heretofore conmaintain the structed as well as at a reduced speed as The area of compared with such machines. ground necessary for starting and landing will thus be reduced accordingly.

It should be understood that the number of propellers may be varied as desired.

What I claim is 1. In an aeroplane, the combination of a fuselage, having a roof inclined in all directions, a tractor propeller, a lifting propeller at the top of said roof, supporting planes attached to said roof in such a way as to form spaces between themselves and said roof, steering planes, a freely rotating nose at the front end of the fuselage behind the tractor propeller, said nose carrying helical ribs on its external surface, and a shield coveringthe periphery of the lifting propeller at a portion thereof, where thepropeller moves forwardly relatively to the. fuselage.

2. In an aeroplane, a fuselage, a freely rotating nose at the front end of the fuselage, a tractor propeller in front of said nose, a roof 011 said fuselage inclined in all directions, a lifting propeller above said roof, 2. pair of supporting lanes immediately below the level of said planes having openings formed in them to allow the air depressed by the lifting propeller to enter under said planes, another pair of supporting planes substantially at the level of the shaft of the tractor propeller, and a shield covering part of the periphery of the lifting propeller.

In testimony whereof I have signed my name.

DAVID K. J

lifting propeller, said 

